The present invention relates in general to an internal combustion engine system of the type having a fuel supply tank, fuel injection means operating preferably with Diesel fuel and including a fuel injection pump provided with a suction chamber, means for adjusting the amount of injected fuel, a fuel supply pump normally connected via a supply conduit between the fuel supply tank and the suction chamber of the fuel injection pump. In particular, this invention relates to a control device for inactivating the internal combustion engine of the system, the control device including a suction device connection to the suction space of fuel injection pump to empty the suction space in response to any malfunction of the fuel injection means, and means for verifying the operativeness of the suction device.
A control device of this kind is known from the German publication DE-OS R. 18,356, assigned to the same assignee.
Diesel engines are equipped usually with a mechanically driven fuel injection pump. The amount of injected fuel and thus the engine performance is determined by an adjusting mechanism. This adjusting mechanism is actuated either hydraulically or electromagnetically and includes fuel quantity regulating elements, such as a control rod of a series-connected pump whose position determines the amount of injected fuel. During the operation of the engine it may happen, however that the control rod is stuck, for example, due to the penetration of a foreign particle. The operator of the internal combustion engine system, for example a driver of a motor vehicle in which the engine is installed, has no longer any control of the operational behavior of the vehicle. In the event when the regulating or control rod is stuck in a position corresponding to a high dosing of the fuel, the rotary speed of the engine rises to an unacceptable level, the engine is also supplied with an excessive amount of fuel. Under these condition the risk of accidents is substantially increased.
In order to facilitate fast emergency disconnection of the internal combustion engine, particularly in a vehicle operating with Diesel fuel, it has been devised that in the case of a clamped regulating rod the fuel supply be interrupted as fast as possible and in addition, the suction chamber of the fuel injection pump be emptied. The beforementioned prior art suction device employs for this purpose an additional suction device and an electromagnetically controlled stop valve. The disadvantage of this known solution is the fact that the operativeness of the prior art control device for inactivating the internal combustion engine cannot be supervised without further measure, particularly it cannot be verified by the user of the motor vehicle.